Phosphorus containing materials, their preparation and use

ABSTRACT

The present invention is directed towards phosphorous containing organic materials, processes for making them and uses thereof. These materials preferably impart and/or exhibit resistance to attack, for example they may be useful as flame retardant additives and/or materials. The materials are especially radiation-curable polyester polymers. The phosphorous component used has at least one P—C bond resistant to hydrolysis or transesterification. It can be bis(hydroxymethyl)isobutylphosphineoxide, bis(hydroxypropyl)isobutylphosphine oxide and trishydroxymethylphosphine oxide. In other embodiments, it is 9,10-dihydro-9-oxa-10-phosphaphenantrene-10-oxide.

[0001] The present invention is directed toward phosphorus containingorganic materials, processes for making them and uses thereof. Thematerials of the invention may preferably impart and/or exhibitresistance to attack, for example they may be useful as flame retardantadditives and/or materials.

[0002] There is a continuing need for new materials exhibiting animproved resistance to attack, for example improved flame retardants.Furthermore, there is a need for materials which, while possessing theabove properties, are polymerisable, for example in the form of acoating, as a thin or thick layer. Polymerisation may be achieved by anysuitable method. Preferred methods are thermal curing or irradiation,for example using ultraviolet radiation and/or ionising radiation, suchas gamma rays, X-rays or an electron beam.

[0003] The use of phosphorus containing materials as flame retardants iswell known. It is believed that in the presence of a flame source theyact by, for example, forming phosphoric and polyphosphoric acids of lowvolatility which catalyse the decomposition of organic compounds tocarbon (char) and water. Non volatile phosphorus containing compoundsmay also coat the char to protect it from further oxidation, and thismay act as a physical barrier and/or reduce the permeability of thechar. It is believed that in general the greater the phosphorus contentof the material the better its flame resistance.

[0004] It will be appreciated that the desire for imparting improvedflame resistance by incorporating an increasing phosphorus content mustalso be balanced by the corresponding reduction in the proportion ofother components in the treated or modified material. The overallphysicochemical and mechanical properties of the resultant material mustbe maintained within limits acceptable for its end use.

[0005] Many previous phosphorus containing flame retardants have beennon-copolymerisable compounds and/or required additional halogenatedcompounds as additives to improve flame retardant properties. Inconventional plastics, flame retardation of polymers has been achievedby the use of flame retardants as additives, which are physicallyblended as a mixture with the polymer. However, conventional flameretardant additives suffer from several drawbacks. Prior art additivesmodify the physical and mechanical properties of the polymer often in anundesirable or unpredictable way. There may also be compatibilityproblems with the additive and the polymer to which it is added.Additives can also be unacceptable for certain applications, especiallyfor coatings, as they can migrate through the coating to the surfacewhich can lead to blooming phenomena. Additives may also discolour thecomposition which is a particular issue for clear coatings. Furthermorethe use of certain additives may not work well with radiation curablematerials since the high concentration of additives could lead toincomplete curing because the additive absorbs radiation.

[0006] For all these reasons, co-polymerisable compounds containingphosphorus have been developed in which the phosphorus atom is linked tothe backbone of a polymer precursor through a chemical reaction in whicha covalent bond is formed. This method of incorporating phosphorus isadvantageous because as the phosphorus moieties are permanently linkedto the backbone of the resultant polymer, there is no blooming effectand there are no compatibility issues as can be the case whenincorporating phosphorus containing additives. Use of phosphorouscontaining polymer precursors also has a reduced influence upon thephysical and mechanical properties of the resultant polymer. For examplesolid flame retardant additives can undesirably increase the viscosityof a polymer to which they are added.

[0007] Polyester acrylates (PEA) and polyester urethane acrylates (PEUA)(together both also referred to as polyester acrylates) represent animportant polymer class of radiation curable polymer as they are oftenused as polymer precursors to- make polymer coatings (such as UV curableresins and UV curable powder coatings) for thermally sensitivesubstrates such as wood or MDF. Therefore it would be desirable toincorporate phosphorous in polyester acrylates to provide these polymerswith intrinsic flame retardant properties, particularly as safetyregulations become more stringent.

[0008] However the oxyphosphorus groups previously used to incorporatephosphorous in polymers to impart flame resistance are sensitive towardhydrolysis and a transesterification reaction at a oxyphosphorous group(P—O bond) such as in a phosphate or phosphonate group. Moreover in thecase of hydrolysis the mechanism is mostly irreversible. Indeed it iswell known that direct esterification of any of the phosphoric acids isdifficult. For example it is not feasible to prepare a trialkylphosphate by heating H₃PO₄ with an alcohol as the reaction is sluggishand requires high temperatures for lengthy periods (for example see page33 of “The Chemistry and Uses of Fire Retardants”, John W; Lyons,Wiley-Interscience, 1970). This limits the way these phosphorous groupscan be covalently bound to a polyester as a conventional esterificationreaction which might be used to bind these derivatives to a polyesteracrylate polymer cannot be used. The reaction involves acid catalysiswhich would also lead to transesterification side reactions at theoxyphosphorous group.

[0009] The applicant has demonstrated these side reactions by reactingprior art phosphorus containing polyols (e.g. those availablecommercially from Akzo Nobel under the trade name Fyrol 6) with acrylateesters. Even under the mild reaction conditions required for thisreaction transesterification occurs preferentially at the phosphoruscontaining carbon followed by intramolecular cyclisation. This confirmsthat acrylation of prior art phosphorus containing polyols havingphosphonate groups (which are supposed to be more resistant towardhydrolysis and/or transesterification reactions than phosphate groups)leads to a transesteriflcation reaction. Thus prior art phosphorouscontaining polyols are not suitable derivatives for making phosphoruscontaining polyester acrylates.

[0010] Thus it would be desirable to find reagents having oxyphosphorusgroups with a high resistance toward hydrolysis and/ortransesterification reactions, to prepare the new and useful class ofphosphorus containing polyester acrylate polymers.

[0011] The prior art will now be discussed:

[0012] J. Appl. Polym. Sci., 74(10), 2499-2509 by B I Wang, Ta-Zen:Chen, Kan-Nan at Department of Chemistry, Tamkang University, Tamsui251, Taiwan describes how covalently bonded phosphorus was introducedinto an aqueous-based polyurethane system using a postcuring reaction.Anionic aqueous based polyurethane (PU) dispersions were derived from awater dispersion process in which PU prepolymers having carboxylicgroups were polymerised with neutralisation and chain extension. ThesePU prepolymers were prepared from a conventional polymerisation additionof isophorone diisocyanate, polypropylene glycol-1000, anddimethylolpropionic acid. Covalently bonded phosphorus was introducedinto the PU by a phosphorus-containing curing agent. A series ofphosphorus and multi-aziridinyl groups containing curing agents weresynthesized for this purpose. Each of them served in a dual-functioncapacity as a postcuring agent for the anionic aqueous based PU system.The resulting postcured PU is stated to exhibit flame inhibitingproperties due to the presence of nitrogen and phosphorus content.However in these polymers the phosphorous component is part of thecrosslinker rather than the main polymer backbone.

[0013] JP 08199092 describes polyester resins for fire retardant powdercoatings consisting of aromatic dicarboxylic acid component andaliphatic glycol component copolymerised with phosphorus containingcompound.

[0014] JP 11293004 describes flame retardant polyester film made frompolyester resin containing an aromatic dicarboxylic acid and aphosphorus compound. These resins are not copolymerisable by UVradiation.

[0015] WO 9942522 describes halogen-free flame retardant resincompositions comprising blends of polyester and red phosphorus powderfor use in electrical and electronic components. These resins are notcopolymerisable by UV radiation and phosphorus is used as additive (notcovalently bound to the polymeric backbone).

[0016] There are certain reference describing resins with a phosphoruscomponent grafted onto a polyester backbone.

[0017] For example EP 826712 describes polyesters derived from reactivephosphinic acid compounds.

[0018] DE 4344691 describes non UV copolymerisable polyethyleneterephthalate polymers modified with phosphorus containing units in thepolymer chain and phosphorus modified polyesters derived therefrom.

[0019] JP 07081015 describes a laminated polyester film having goodtransparency, electrostatic properties and adhesion. There is no mentionthat this polyester has flame retardant properties or is UVcopolymerisable.

[0020] JP 63277233 discloses an aromatic copolyester for films, etc,with heat stability containing phosphorus containing aromatic diol,terephthalic acid, 4-hydroxybenzoic acid and acetic anhydride. Thispolyester is based on a phosphorous containing diol and is notUV-curable.

[0021] DE 3532865 discloses saturated hydroxylated polyesters containingacidic phosphoric acid ester groups used in combination withpolyisocyanates, to form two-component polyurethane lacquers for paint.To extend their pot life these polyesters contain volatile tertiaryamines or amides. These polymers are not UV curable.

[0022] DE 3200824 describes a fire retardant PVC coated polyester webmade from polyester with integral phosphorus containing fire resistantmodifier and PVC coating and plasticiser and antimony oxide. This is notUV copolymerisable.

[0023] U.S. Pat. No. 4,315,969 describes a phosphorus containingpolyester which is not copolymerisable.

[0024] U.S. Pat. No. 4,259,222 describes a non copolymerisable linear,saturated polyester containing phosphorus and halogen by reactingphosphorus acid with halogenated aromatic ether diols.

[0025] There are some references which describe blends of polyester withphosphorus derivatives (not covalently bound thereto).

[0026] EP 0305745 describes a flame retardant unsaturated polyestercomposition containing a nitrogen-phosphorus component, ammoniumpolyphosphate and aluminium oxide. This blend of phosphorus derivativeswith polyester is not UV copolymerisable.

[0027] JP 03281670 describes a flame retardant modification of UVcurable resins with monomers containing bromine and phosphorus. Anoligomeric acrylate ester and polyurethane acrylate are effectivelyretarded with vinyl-type flame-retardant monomers containing both Br andP.

[0028] Journal of Applied Polymer Science, Vol. 72, 109-122 (1999),“Synthesis and characterisation of copolyesters containing thephosphorus linking pendent groups” Shinn-Jen Chang, Fen-Chih Chang andU.S. Pat. No. 5,650,531 are two related references which both describe ahighly pendant phosphorus-containing reactive polyester copolymer. Theseoligomers are synthesised by first esterifying diols, unsaturated doublebond-containing dicarboxylic acids or acid anhydrides and saturateddicarboxylic acids or acid anhydrides to form a phosphorus freeoligomeric unsaturated polyester. The phosphorus-containing reactivepolyester oligomer is then formed by grafting a phosphorus-containingcompound of formula:

[0029] (where A is —R or OR and R is a C₁₋₁₀ alkyl group or asubstituted or unsubstituted phenyl group) onto the oligomericunsaturated polyester through addition reaction preferably in thepresence of a selected metal complex catalyst such as H₂PtCl₆.

[0030] However this reference does not appreciate the problem of sidereactions such as esterification and hydrolysis which can occur whenincorporating such phosphorus-containing groups in a polyester.Phosphorous compounds where A is OR would not produce oligomers asdescribed in this patent as with two OR groups at the P centre, thegroup would hydrolyse under the reaction conditions described. Indeed noexamples or characterisation data (such as ³¹P NMR data) is given inthis patent to indicate that such oligomers were in fact prepared withthe claimed structure where A is OR. Even compounds mono substituted byOR (when A is R) are still prone to irreversible hydrolysis because theP—OR group is not stabilised (e.g. by forming part of a ring). Thedescribed process therefore does not work as suggested and well ashaving other disadvantages such as the use of an expensive platinumcatalyst and a multiple step synthesis.

[0031] So this reference teaches away form the present invention whichuses a single step process from readily available inexpensive startingmaterials and/or catalysts to produce reactive polyester oligomers of adifferent structure (the First Polymers of the present invention) wherethe phosphorous can be introduced at any point in the polymer chain.

[0032] Polymer 40 (1999) 4387-4398: “Synthesis and properties ofphosphorus containing polyarylates derived from2-(6-oxido-6H-dibenz<c,e><1,2>oxaphosphorin-6-yl)1,4-dihydroxyphenylene”Wang Chun Shan, Lin Ching Hsuan: describes a polyester synthesised froma phosphorous compound obtained by reaction of9,10-dihydro-9-oxa-10-phosphaphenantrene-10-oxide (also referred toherein as “DOPO”) with benzoquinone: Acrylation of these polyesters isnot described.

[0033] European polymer Journal 35 (1999) 1465-1472 “Phosphoruscontaining PET and PEN by direct esterification” C. S. Wang, J. Y.Shieh, Y. M. Sun disclose synthesis of copolyesters based on DOPO anditaconic acid monomers.

[0034] The following references describe phosphorus containing glycidylethers but these polymers are not acrylated: Journal of Polymer ResearchVol.5, n^(o)2, 59-65, April 1998 “Synthesis, characterisation, Thermaland Flame retardant properties of Novel Aryl phosphinate diglycidylether cured with anhydride”, Ching-Sheng Cho et al

[0035] Polymer vol. 39 n^(o) 23 (1998) “Synthesis and properties ofepoxy resins containing2-(6-oxido-6H-dibenz<c,e><1,2>oxaphosphorin-6-yl)1,4-benzene diol”Chun-Shan Wand, J. Y. Shieh.

[0036] Journal of Applied polymer Science, vol., 73, 353-361 (1999),“Phosphorus-containing epoxy resin for electronic application” Chun-ShanWang, Jeng-Yueh Shieh.

[0037] Thus the prior art describes polyester containing phosphorus orblends of polyester acrylates with non radiation curable phosphorusadditives but does not disclose polyester acrylates which containingphosphorus. Flame retardant acrylated polyesters which are curable underUV/EB are unknown. The prior art monomers used previously to introducephosphorous into polyester copolymers have various disadvantages as forexample they are susceptible to hydrolysis and/or transesterification.Thus introducing (meth)acrylate by direct esterification or bytransesterification to get a UV copolymerisable polyester(meth)acrylateis difficult. Moreover prior art processes use expensive catalysts suchas H₂PtCl₆, require multiple steps and/or can only introduce phosphorousgroups into a polymer when they are pendant from the main polymerbackbone.

[0038] Thus there is an ongoing need to find improved means forintroducing phosphorous into organic materials to produce materials withimproved properties effective for the uses and/or applications describedherein and which are capable of being produced on an industrial scaleeconomically. A demand exists for a simple and economical process forthe preparation of compounds which comprise phosphorus atoms and whichcan be used as starting material in the preparation of more complexcompounds exhibiting useful properties for the applications and/or usesdescribed herein (preferably for use in flame-retardancy).

[0039] It is an object of the invention to provide improved phosphorouscontaining materials which solve some or all of the problems describedherein for the prior art.

[0040] The applicant has developed new improved phosphorous containingmaterials which exhibit utility in the applications described herein,for example having improved flame retardant properties and that areradiation curable. The applicant has also discovered improved processesfor preparing such materials which address some or all of the problemsof the prior art such as those described herein.

[0041] The use of a halogen containing monomer to prepare a flameretardant composition is undesirable. In a fire halogen groups cangenerate toxic and corrosive combustion products. These corrosive gases,in addition to their toxic properties, cause significant damage toelectronic components, present in particular in computers, which veryoften results in the loss of essential data and irreparable damage,often worse than the fire itself. The combustion products from halogencontaining materials may even be as dangerous as combustion productsfrom materials untreated with flame retardants. It is also undesirableto use halogen compounds for other reasons such as their potentiallyundesirable effect on the environment. Therefore preferably the polymersof the invention are substantially free of halogen.

[0042] The applicant has now prepared in a single step (“First Process”)certain phosphorus containing acrylatable (e.g. hydroxy and/or carboxyterminated) reactive oligomers (“First Polymer”). These First Polymerscan be used in a Second Process to prepare (as a “Second Polymer”) a newclass of phosphorous containing polyesters such as polyester acrylatesand/or polyester urethane acrylates. This because the plurality ofacrylatable functional groups in the First Polymer (for example two ofmore hydroxy groups if the First Polymer is OH terminated) can beacrylated without hydrolysis or transesterification side reactions atthe oxyphosphorous bond. The Second Polymers can be used in a further(Third) process to form Third Polymers (such as polymerised cross-linkedpolymer networks) useful for example as coatings. Optionally the ThirdProcess is performed in situ on for example an article coated with oneor more Second Polymers.

[0043] Certain polyfunctional reagents described herein (components (i)to (iv) see below) react in a single pot polycondensation (FirstProcess) to form a First Polymer.

[0044] The First Polymer is reacted with at least one acrylating agentto form a radiation-curable polymer precursor (“Second Polymer”). Theterm “acrylating agent” is used herein to refer to a compound comprisinga) one or more optionally alkylated acrylate group(s), for example(meth)acrylate; one or more alkyl(alkyl)acrylate ester(s), for examplealkyl(meth)acrylate ester, preferably methyl(meth)acrylate ester and/orethyl(meth)acrylate ester which can react with said reagent by atransesterification reaction.

[0045] The First Polymer can also be reacted with one or moreoxiranating and/or isocyatating agent. The term “oxiranating agent” isused herein to refer to a compound comprising one or more oxiranylgroup(s), for example oxirane(s) such as epoxides and/or oxetanes. Theterm “isocyanating agent” is used herein to refer to a compoundcomprising one or more isocyanate groups, e.g. —N═C═O. Collectivelyspecies which are (alkyl)acrylatable, oxiranatable and isocyanatable canbe referred to herein as “reactive” as the context dictates.

[0046] The First Polymers may be represented schematically by thefollowing general structure (which is by way of illustration only asshould not be considered as limiting to scope of the invention):

[0047] where T represents the (at least two) reactive groups such ashydroxy and/or carboxy and (P) denotes phosphorus groups which at anyposition on the polymer such as may be pendant from and/or incorporatedinto the main polymer chain (polymer backbone). The First Polymer ispreferably a phosphorus-containing reactive polyester oligomer which maybe dihydroxy or dicarboxy terminated.

[0048] The First Polymer can be reacted with many reagents (SecondReagents) in a Second Process to form a Second Polymer.

[0049] To form a Second Polymer of an acrylate urethane ester, theSecond Reagents may comprise monoisocyanates, for exampleisocyanatealkyl(alkyl)acrylates, such as:

[0050] To form a Second Polymer of an acrylate ester the Second Reagentsmay comprise (alkyl)acryloyl groups for example:

[0051] where in both the preceding formulae LG denotes a leaving groupunder the conditions of the Second Process such as halogen group (e.g.Cl).

[0052] To form a Second Polymer of a urethane acrylate and/or of apolyurethane acrylate dispersed and/or diluted in water, the SecondReagent(s) may comprise a plurality of (preferably two) isocyanategroups (i.e. comprise polyisocyanates).

[0053] To form a Second Polymer of a UV curable powder composition theSecond Reagent(s) may comprise glycidyl(meth)acrylate groups.

[0054] In a preferred Second Process the First Polymer can be preferably(meth)acrylated or transesterified with (alkyl)(meth)acrylate esters toform a preferred Second Polymer which may be represented schematicallyby for example the following structure (which is by way of illustrationonly as should not be considered limiting to the scope of theinvention):

[0055] where independently each R′ is typically H or alkyl such asmethyl.

[0056] The Second Polymers comprise a new class of phosphorus containingpolyester and/or urethane acrylates which can themselves be polymerprecursor(s).

[0057] The Second Polymer can be further reacted with many reagents(Third Reagents) in a Third Process to form a Third Polymer.

[0058] The Second Polymer can also be used as the starting material in aThird Process of polymerisation (e.g. initiated by radiation) to form,as a Third Polymer, a phosphorus-containing polyester derived polymer.For example the Third Polymer may comprise the polymerisation product ofa UV curable polyester acrylate or urethane acrylate after UVirradiation. The Third Process may optionally be carried out in situ(for example by UV irradiation of an article coated with a powdercomposition comprising the Second Polymer) to form as the Third Polymerfor example a coating of a cross-linked polymeric network. Because suchcoatings contain phosphorous they may impart flame retardant propertiesto the coated article.

[0059] First Process

[0060] Therefore broadly in accordance with one aspect of the presentinvention there is provided a First Process for preparing aphosphorus-containing polymer precursor which polymer precursor is aradiation-curable polyester, the process comprising the steps of

[0061] (a) mixing together:

[0062] (i) a compound containing at least one hydrocarbylidenicallyunsaturated group and a plurality of carbonyloxy groups;

[0063] (ii) optionally a compound having a plurality of carbonyloxygroups and optionally free of hydrocarbylidenically unsaturated groups,

[0064] (iii) a polyol, and

[0065] (iv) an oxyphosphorous-containing compound (component (iv)) inwhich the phosphorous atom has at least one P—C bond which is resistantto hydrolysis or transesterification under the reaction conditionsherein; such component (iv) comprising compounds of formula (I) and/or(II) and/or effective isomers, salts and mixtures thereof:

R¹ R² R³P═O   (I)

[0066]

[0067]  where,

[0068] in formula (I): at least R¹ and R² independently representsC₁₋₂₀organo group substituted by one or more hydroxy and/or carboxygroup; R³ represents H or optionally substituted C₁₋₂₀organo group;

[0069] in formula (II): the phosphorous atom is substituted with atleast one carbon atom to form at least one P—C bond; the P—O bond formspart of an organo ring, the ring being optionally substituted with oneor more organo groups and/or optionally fused to one or more otherorgano rings;

[0070] (b) initiating polymerisation of the mixture to form a hydroxyand/or carboxy terminated phosphorous containing polyester oligomer(“First Polymer”),

[0071] Preferably steps (a) and (b) are carried out in a single vessel,more preferably are simultaneous.

[0072] Preferably in step (b) the polymerisation is polycondensation. Acatalyst component (v) may be present during step (a). If present, it isother than one selected from PtCl₄, NiCl₄, PdCl₄, platinium divinyltetramethyldisiloxane, platinium cyclovinyl methyl siloxane and mixturesthereof.

[0073] Preferably, a catalyst is present during step (a) which catalyst(component (v)) comprises a tin complex catalyst.

[0074] In addition to the components (i) to (v) above an additionalingredient [component (vi)] may also be added containing an ionic groupor ionisable group (under the conditions of the reaction) which acts toimprove the aqueous dispersiblity of some or all of the components inthe reaction medium (as for example water may be a product of thepolycondensation). Preferably component (vi) is selected from one ormore of: sulphoisophtahlic acid, isomers and/or salts thereof(preferably the sodium or lithium salt of 5-sulphoisophtahlic acid, thesodium salt thereof also referred to herein as SSIPA);dimethylolpropionoic acid (also referred to herein as DMPA) and/or anyeffective mixtures thereof.

[0075] Component (a)(i)

[0076] Preferably in step (a) of the First Process component (i)comprises a double bond-containing unsaturated dicarboxylic acid, acidanhydride; ester; other condensable derivatives thereof; and/or suitablemixtures thereof.

[0077] More preferably component (i) comprises those compounds ofFormula 1

[0078] where

[0079] w, x, y and z independently represent 0 or 1;

[0080] at least two of R^(a) to R^(d) comprise a monovalent carboxygroup or together comprise a divalent carbonyloxycarbonyl group; theremaining groups R^(a) to R^(d) independently representing H oroptionally substituted C₁₋₁₅hydrocarbyl; and/or effective isomers,esters and/or salts thereof.

[0081] Most preferred compounds of Formula 1 are those where

[0082] either w, x, y and z are all 0 or

[0083] one of w, x, y and z is 1 the rest being 0;

[0084] where the at least two of R^(a) to R^(d) which comprise amonovalent carboxy group or together comprise a divalentcarbonyloxycarbonyl group is adjacent the methylene group;

[0085] the remaining groups R^(a) to R^(d) independently representing Hor C₁₋₁₅hydrocarbyl; and/or effective isomers, esters and/or saltsthereof.

[0086] Component (i) may usefully comprise at least one unsaturateddiacid and/or anhydride selected from

[0087] in which R^(a), R^(b), R^(c) and/or R^(d) independently representas appropriate H or C₁₋₁₅hydrocarbyl;

[0088] and/or effective isomers, (alkyl)esters and/or salts thereof.

[0089] Specific unsaturated diacids and/or anhydrides which may comprisecomponent (i) are:

[0090] To inhibit the self-polymerisation of component (i) (e.g.unsaturated dicarboxylic acids; anhydrides and/or their esterderivatives) it is preferred to add a double bond polymerisationinhibitor, for example, a quinone, such as hydroquinone, butyl quinone,dibutyl hydroquinone, methyl hydroquinone, during the First Process(e.g. polycondensation/esterification reaction) of the presentinvention. The amount of the inhibitors added is preferably from about500 ppm to about 3000 ppm based on the total amounts of ingredients inthe reaction mixture.

[0091] Component (a)(ii)

[0092] Preferably in step (a) the optional component (ii) comprises aunsaturated or saturated dicarboxylic acid or an acid anhydride thereof.Most preferably component (ii) is saturated. Examples of saturateddicarboxylic acids, esters or anhydrides that may comprise component(ii) herein are one or more of: adipic acid (HOOC—(CH₂)₄—COOH), sebacicacid, azelaic acid, docecane dicarboxylic acid, diesters of these acids,and/or effective mixtures thereof.

[0093] Component (a)(iii)

[0094] Preferably in step (a) component (iii) comprises an saturateddiol. More preferably diols that may comprise component (iii) compriseone or more of: ethylene glycol, 1,4-butane diol, 1,6-hexanediol,diethylene glycol, neopenthylglycol, isomers, alkoxylated derivativesthereof (usefully oxypropylated and/or oxyethylated derivatives thereof)and/or effective mixtures thereof.

[0095] Component (a)(iv)

[0096] Conveniently in step (a) component (iv) (the oxyphosphorouscontaining compound) comprises a tertiary organo-substituted phosphorusatom (preferably comprising 3×P—C bonds thereon) or a secondary organosubstituted phosphorus atom (preferably comprising 2×P—C bonds and oneresistant oxyphosphorous bond (P—O) thereon).

[0097] A resistant oxyphosphorous bond denotes a P—O bond which does nothydrolyse and/or undergo transesterification under the conditions of thereaction (e.g. due to steric hindrance at the phosphorous and/or oxygenatom(s)) or where such hydrolysis and/or transesteriflcation is readilyreversible under the conditions of the reaction (e.g. where both thephosphorous and oxygen atoms of the P—O bond are ring atoms in a largercyclic group).

[0098] More conveniently component (iv) comprises compounds of Formulae1, 2, I, Ia, Ib, II, IIa, IIb, as described herein and/or effectiveisomers, salts and/or mixtures thereof.

[0099] Compounds of Formula 1 are represented by:

(R¹)₃P(═O)_(m)   Formula 1

[0100] where m is 1;

[0101] the phosphorous atom is substituted directly with at least twocarbon atoms to form at least two P—C bonds; each R¹ independentlyrepresents H or optionally substituted C₁₋₂₀organo;

[0102] at least two R¹ groups being optionally substituted with one ormore hydroxy and/or carboxy; and/or

[0103] effective isomers, salts and/or mixtures thereof.

[0104] The same compounds can be defined more clearly as compounds offormula (I):

R¹ R² R³ P:=0   (I)

[0105] where at least R¹ and R² independently represents C₁₋₂₀organogroup substituted by one or more hydroxy and/or carboxy group; R³represents H or optionally substituted C₁₋₂₀organo group.

[0106] Preferably each R¹ independently represents H or optionallysubstituted C₁₋₁₅hydrocarbo; more preferably H or optionally substitutedC₁₋₁₂alkyl.

[0107] Preferred compounds of Formula I comprise those of Formulae Iaand/or Ib and/or effective isomers and/or salts thereof:

[0108] Other preferred compounds are phosphine oxide available fromCYTEC under the tradename Cyagard RF 1241(Bis(hydroxymethyl)isobutylphosphine oxide, Cyagard RF 1243(Bis(hydroxypropyl)isobutylphosphine oxide) and THMPO(trishydroxymethylphosphine oxide).

[0109] Phosphine oxide Cyagard RF 1243 is:

[0110] Tris(hydroxymethyl)phosphineoxide (THMPO) is:

[0111] The phosphine oxide Cyagard RF 1241 is:

[0112] Other preferred compounds of formula (I) are phosphine oxidecompounds bearing two carboxy groups such as, for example:

[0113] Compounds of Formula II are represented by:

[0114] where the phosphorous atom is substituted with at least onecarbon atom to form at least one P—C bond;

[0115] the P—O bond forms part of a larger organo ring (denoted by thearc of a circle in Formula II), the ring being optionally substitutedwith one or more organo groups and/or optionally fused to one or moreother organo rings:

[0116] and/or effective isomers, salts and/or mixtures thereof.

[0117] Preferred compounds of Formula II comprise compounds of FormulaIIa

[0118] in which

[0119] R² to R⁵ independently represent H or optionally substitutedC₁₋₁₈organo group(s), a plurality of which may together represent one ormore rings optionally fused to the oxyphosphorous ring to which they areattached; and/or effective isomers, salts and/or mixtures thereof.

[0120] More preferred compounds of Formula II comprise compounds ofFormula 2.

[0121] in which

[0122] p and q independently represent 0 or an integer from 1 to 4;

[0123] R⁶ and R⁷ independently in each case represent H or optionallysubstituted C₁₋₁₅hydrocarbo group(s) and/or optionally one or more rings(aromatic or non aromatic) fused to the benzene ring(s) to which theyare attached; and/or effective isomers, salts and/or mixtures thereof.

[0124] A preferred compound of Formula II comprises that of Formula IIb:

[0125] 9,10-dihydro-9-oxa-10-phosphaphenantrene-10-oxide (also referredto herein as “DOPO”) and/or effective isomers, salts and/or mixturesthereof.

[0126] Component (a)(v)

[0127] Conveniently the optional catalyst, if present, may besubstantially free of any of the following: PtCl₄, NiCl₄, PdCl₄siloxanes of Pt, (especially platinum divinyl tetramethyldisiloxane andplatinum cyclovinyl methyl siloxane); and/or mixtures thereof. Moreconveniently the catalyst is substantially free of platinum, palladium,nickel, complexes and/or salts thereof. Most conveniently the catalystmay be other than a metal complex represented by formula MX₄ or H₂MX₆where M is a metal of Group 10 (IUPAC) of the periodic table (=GroupVIIIA in Europe and VIIIB in USA) and X is a halogen or a group of S, Oor Si.

[0128] Preferably the optional catalyst used as component (v) hereincomprises a main group metal (i.e. non transitional metal), complexand/or salt thereof, more preferably a metal, complex and/or salt ofGroup 14 (IUPAC) of the periodic table (=Group IVB in Europe and IVA inUSA); most preferably comprises tin metal, complex and/or salt, forexample the tin complex available commercially from Goldschmidt underthe trade name Fascat 4102.

[0129] The amount of the catalyst used may be from about 0.003% to about0.05% percent by weight based on the total amount of the othercomponents.

[0130] The First Process of the present invention for preparing theFirst Polymer has several advantages compared to known methods ofpreparing prior art phosphorus-containing reactive polyester oligomers.These advantages may include one or more of the following:

[0131] excellent yields (very few side reactions, so purification isunnecessary);

[0132] inexpensive catalyst such as tin are used: (compared to Group 10catalysts used in the prior art); and/or

[0133] phosphorous groups can be readily introduced in any region in thepolymer e.g. pendant from the polymer chain and/or within the mainpolymer backbone.

[0134] First Polymers

[0135] Another aspect of the invention provides as the First Polymer ofthe invention a phosphorus-containing reactive polyester oligomerobtained and/or obtainable from the First Process of the invention asdescribed herein.

[0136] The First Polymers are preferably reactive (i.e.(alkyl)acrylatable; oxiranatable and/or isocyanatable) in a SecondProcess to form as a Second Polymer of the invention aphosphorus-containing unsaturated polymerisable polymer (see below).

[0137] Preferably the First Polymer has a molecular weight (M_(n)measured by GPC) less than about 5,000 daltons; more preferably fromabout 250 to about 4,000 daltons, most preferably from about 300 toabout 3,000 daltons, for example from about 300 to about 2,000 daltons.

[0138] Preferably the First Polymer has a viscosity of from about 100 toabout 70,000 mPa.s,. more preferably from about 1000 to about 50,000mPa.s, most preferably from about 10,000 to about 40,000 mPa.s. Theviscosity values quoted herein are Hoppler viscosities measured at 60°C.

[0139] Preferably the First Polymer has a phosphorus content of fromabout 0.5% to about 10.0%; more preferably from about 2.0% to about8.0%; most preferably from about 4.0% to about 7.0% by mass of the FirstPolymer.

[0140] Preferably the First Polymer has a polydispersity of at leastabout 1.1, more preferably from about 1.2 to about 4.0 and mostpreferably from about 1.5 to about 3.5.

[0141] Where the First Polymer comprises a plurality of hydroxy groupsit may be used as the polyol component for the preparation ofphosphorous containing urethane acrylate polymers. This method hasseveral advantages over known methods for preparing urethane acrylatesfrom phosphorus-containing polyols (such as described in WO 9502004[DSM]), and such advantages may include one or more of those describedherein.

[0142] The applicant's patent application WO 00/52016 (the contents ofwhich are hereby incorporated by reference) describes polymer precursorsformed by the reaction of an optionally substituted terminal phosphateor H-phosphonate ester with a compound comprising at least one oxiranyl,preferably epoxy, ring adjacent an alkylenylcarbonyloxy group. ThereforeFirst Polymers of the present invention which comprise at least twohydroxy groups may also be copolymerised with the aforementioned polymerprecursors described in WO 00/52016 to produce phosphorus containingpolyurethanes copolymers which for example may have use as flameretardants, anti-corrosives, pigment dispersants and/or adhesionpromoters.

[0143] However it is preferred that First Polymers are used as describedherein in the Second Process of the present invention to form SecondPolymers of the present invention (e.g. acrylated polyester polymerprecursors).

[0144] The First Polymer comprises phosphorus moieties which may bependant to or part of the main polymer chain and thus also may bependant to or part of the main polymer chains in the Second and ThirdPolymers derived therefrom. This has the advantage that a phosphorous tocarbon bond which is resistant to hydrolysis and oxidation can beintroduced into polymers to modify and/or alter the physicochemical andmechanical properties of the phosphorus containing polymers of theinvention.

[0145] If the First Polymer is substantially free of P—O single bonds(for example if component (iv) in the First process comprises mainlycompound(s) of Formulae 1, I Ia, Ib) then the First Polymer (and inSecond and Third Polymers derived therefrom) has a high hydrolysisand/or oxidation resistance due to the incorporation of strong P—C bondsin the polymer backbone and scission thereof is very difficult.

[0146] If the First Polymer comprises a P—O single bond (for example ifcomponent (iv) in the First process comprises one or more compound(s) ofFormulae 2, II, IIa, IIb) then preferably the P—O bond is notincorporated into the main polymer backbone (chain) of the First Polymerso hydrolysis of the P—O bond thereon does not lead to scission of themain polymer chain of the First Polymer (and Second and Third Polymersderived therefrom). If hydrolysis and/or transesterification occurs atthe P—O bond on the First Polymer (and in Second and Third Polymersderived therefrom) this is reversible where for example the P—O bondforms part of a larger ring structure.

[0147] Second Process

[0148] The First Polymer is reacted, in a step (c), with at least oneacrylating agent to form a radiation-curable polymer precursor (“SecondPolymer”).

[0149] Therefore broadly in a further aspect of the present inventionthere is provided as the Second Process of the invention a process forpreparing a phosphorus containing polymer precursor (also referred toherein as the Second Polymer), the process comprising the step ofreacting a First Polymer of the present invention as described herein,with at least one reagent (also referred to herein as the SecondReagent) comprising one or more (meth)acrylate, oxiranyl and/orisocyanate group(s).

[0150] Preferably the Second Reagent comprises an acrylate and/oroxiranyl group. More preferred Second Reagents are selected from:(meth)acrylic acids: (meth)acrylate (alkyl)esters;, oxiranyloxycontaining compounds; and most preferably from: (meth)acrylic acidand/or glycidyl(meth)acrylates.

[0151] More preferably the Second Process relates to the preparation ofa phosphorus-containing polymer precursor (the Second Polymer) by direct(meth)acrylation of a phosphorus-containing reactive polyester oligomer(the First Polymer).

[0152] Due to the high hydrolytic resistance in the Second Process ofthe phosphorous carbon chemical bond of the First Polymer it is possibleto react the First Polymer with the Second Reagent to form the SecondPolymer without hydrolysis or transesterification side reactions.

[0153] An alternative preferred Second Process of the inventioncomprises the steps of:

[0154] a) reacting the First Polymer with a polyisocyanate to form anoligomer (which is preferably terminated with an isocyanate (NCO) group)and

[0155] b) end capping any residual isocyanate groups with a suitable endcapping reagent (such as hydroxy(alkyl)acrylate);

[0156] to form, as the Second Polymer, a urethane polymer (for example aurethane acrylate polymer).

[0157] Isocyanates may be used in the Second Process as co(polymerprecursors) with the First Polymer, to form as a copolymer the SecondPolymer.

[0158] Organic isocyanates which may be used to prepare polyurethaneSecond Polymers are preferably polyisocyanates (i.e. have two or moreisocyanate groups per molecule), more preferably di- or tri-isocyanates. The isocyanates may be aliphatic, cycloaliphatic and/oraromatic. Examples of suitable isocyanates comprise any of thosedisclosed in WO 00/52016 (which is hereby incorporated by reference) andespecially those described on page 17, line 14 to page 18 line 6 of thisreference. The total quantity of organic (poly)isocyanates used toprepare Second Polymers may be from about 10% to about 60% by weight ofthe Second Polymer.

[0159] If the Second Polymer comprises a phosphorous containingpolyester urethane acrylate then the Second Process may be solvent free,preferably only reagents being used and optionally may also be free ofany further purification, washing and/or isolation step(s) (work-upsteps).

[0160] Because of their high content of oxyphosphorous groups the SecondPolymers are hydrophillic and so preferably the Second Process of theinvention does not comprise an aqueous washing step. Surprisingly it hasbeen found that a washing step is not required in the Second Process.

[0161] Therefore a preferred aspect of the Second Process of theinvention comprises a further step where the reaction product isneutralised with a weak or strong base (preferably strong base) andwater is removed from the reaction mixture before the resultant productis isolated. More preferably the Second Process comprises a final workup step in which the reaction product is neutralised in situ with astrong base (such as aqueous sodium hydroxide) the water is removed byazeotropic distillation and the resultant product is collected byfiltration. This work up results in significantly less (preferablysubstantially no) mass loss of the hydrophillic Second Polymer and thusmuch higher yields can be obtained.

[0162] The Second Process of the present invention (or preferredfeatures thereof) have several advantages which may include one or moreof the following:

[0163] a means is provided for obtaining a new class of usefulphosphorous containing polymer precursors (the Second Polymers);

[0164] there is a substantial reduction in side reactions such astransesterification and/or hydrolysis of oxyphosphorous groups;excellent yields are obtained as no washing is necessary; so there islittle mass loss of the hydrophillic Second Polymer; and/or

[0165] the process is environment friendly as eliminating a washing stepreduces waste products.

[0166] Second Polymers

[0167] Another aspect of the invention provides as the Second Polymer ofthe invention a phosphorus-containing polymer precursor obtained and/orobtainable from the Second Process of the invention as described herein.

[0168] The Second Polymers comprise phosphorus-containing polyesterswith for example (meth)acrylate, oxiranyl and/or urethane groups andthese can be considered as a novel class of polymer precursors.

[0169] Preferred Second Polymers comprise optionally substitutedphosphorous containing polyester acrylates and optionally substitutedphosphorous containing polyester urethane acrylates; more preferablyphosphorous containing polyester alkyl(meth)acrylates.

[0170] The Second Polymers are phosphorus-containing polymer precursorswith a high phosphorus content and can be used in the applications oruses described herein for example to confer useful properties topolymers. Thus the Second Polymers are particularly useful to preparefurther polymers and/or compositions (such as the Third Polymers of theinvention—see below) useful in at least one of the followingapplications: anti-corrosion, pigmentary dispersion; adhesion promotionand/or flame retardancy, especially flame retardancy. The SecondPolymers may also have and/or impart such properties themselves.

[0171] Compositions comprising the Second Polymer can be cured in a veryconvenient way [e.g. by radiation (UV, EB) or thermal curing (withthermal initiators)] to generate a cross-linked network of polymerchains in situ (the Third Polymer) which form a coating and/or film ofresin (such as polyurethane acrylate or polyester acrylate) which can beflame-retardant.

[0172] Preferably the Second Polymer has an average molecular weight(M_(n)) of from about 200 to about 5,000 daltons; more preferably fromabout 250 to about 4,000 daltons, most preferably 500 to about 3,000daltons. Alternatively the Second Polymer may have a M_(n) value of fromabout 1,000 to about 2,000 daltons. The M_(n) value may be measured byany suitable technique such as GPC.

[0173] Preferably the Second Polymer has a phosphorus content of fromabout 0.5% to about 10.0%; more preferably from about 2.0% to about7.0%; most preferably from about 3.0% to about 6.0% by mass of theSecond Polymer.

[0174] Preferably the Second Polymer comprises optionally substitutedphosphorous containing polyesters such as those selected from: polyesteracrylates; polyester oxiranyl(alkyl)acrylates [more preferably polyesterglycidyl(meth)acrylates]; polyester urethane acrylates; polyurethanedispersions (optionally cross-linkable and/or crosslinked); polyestersand/or optionally cross-linked and/or cross-linkable compositions,mixtures and/or networks thereof.

[0175] Preferably the Second Polymers comprises an average value for thenumber of repeat units per chain (denoted herein by “m”) of from about 2to about 100, most preferably from about 2 to about 50. Preferably thepolymers of the invention comprise a mixture of polymer chains with asubstantially Gausian distribution of chain lengths. Alternatively if mis 1, this represents a monomer.

[0176] Preferably the Second Polymer has a polydispersity of at leastabout 1.1, more preferably from about 1.2 to about 4.0 and mostpreferably from about 1.5 to about 3.5.

[0177] Third Process

[0178] A yet other aspect of the invention provides, as the ThirdProcess of the Invention, a polymerisation method for preparing aphosphorus-containing polyester derived polymer (also referred to hereinas the Third Polymer) in which the method comprises a step of initiatingpolymerisation in the presence of the Second Polymer of the presentinvention which may for example be used as a reagent, and/or co-monomerin combination with other ingredients such as (co)monomers, polymerprecursors, catalysts, initiators (e.g. photo-initiators), cross-linkersand/or other additives (e.g. flame retardant additives).

[0179] Flame retardant additives may be added during the Third Processto improve the flame retardant properties of the cured polymer (ThirdPolymer of the invention) with the advantage that they can be added atmuch lower loading to achieve a given flame retardant effect because theThird Polymer already has flame retardant properties. As such additives(if used) will be present in lower amounts, this limits theircorresponding drawbacks.

[0180] Examples of suitable flame retardant additives comprise one ormore of the following and/or any compatible mixtures thereof:

[0181] phosphorous containing additives such as DOPO, red phosphorous,ammonium phosphates; ammonium polyphosphates, melamine phosphates (e.g.melamine pyrophosphate and/or melamine orthophosphate), aliphaticorganophosphorous additives (e.g. triethylphosphate, tributylphosphate,trioctylphosphate, triphenylphosphate and/or dimethylmethylphosphonate); oligomeric phosphorous compounds; trimethylolpropanemethylphosphonate oligomer, pentaerythritol phosphates and/orpolyphosphazene derivatives;

[0182] inorganic hydroxides such as aluminium trihydroxide, magnesiumhydroxide, brucite, hydromagnesite, aluminium phosphinates, mixed metalhydroxides and/or mixed metal hydroxycarbonates;

[0183] inorganic oxides such as magnesium oxide; and/or antimonytrioxide;

[0184] silicone, silica and/or silicate derivatives; and/or

[0185] other inorganic materials such as magnesium calcium carbonate,barium metaborate; zinc borate, zinc hydroxystannate; zinc stannate;zinc metaborate; expandable graphite; and/or blends of vitreousmaterials that act as a flame retardant barrier (such as that availablefrom Ceepree under the trade name Ceepree 200).

[0186] The flame retardant additives may optionally be surface treatedto improve their compatibility with the polymers to which they areadded. For example inorganic hydroxides may be surface treated with longchain carboxylic acid(s) and/or silane(s) as described in “FireRetardancy of Polymeric Materials”, edited by Arthur F. Grand & CharlesA. Wilkie; Marcel Dekker Inc (5000), pages 285 to 352.

[0187] In the Third Process initiation of polymerisation may be achievedby any suitable means well known to those skilled in the art. Examplesof suitable methods comprise: thermal initiation; chemical initiation byadding suitable agents; catalysis; and/or initiation using an optionalinitiator followed by irradiation, for example with electromagneticradiation (photo-chemical initiation) at a suitable wavelength such asUV; and/or with other types of radiation such as electron beams, alphaparticles, neutrons and/or other particles. Radiation, especially UV orelectron beam (EB) radiation is the preferred initiation means.

[0188] The Third Process of the present invention (or preferred featuresthereof) has several advantages which may include one or more of thefollowing:

[0189] polymer coatings (Third Polymers) of novel structure and/orproperties can be obtained; and/or

[0190] the process is environment friendly as no solvent is required inthe case of UV or EB curing.

[0191] Third Polymers

[0192] Another still further aspect of the invention provides as theThird Polymer of the invention a phosphorus-containing polyester derivedpolymer obtained and/or obtainable from the Third Process of theinvention.

[0193] Preferably the Third Polymer of the invention comprises a resinwhich Is substantially cross-linked to form a network of linked polymerchains which may form for example a film or coating and may contain oneor more pendant phosphorus moieties within the polymer chain or network.

[0194] A yet still other aspect of the invention provides an (optionallyflame retardant) coating composition comprising a Third Polymer of thepresent invention. Preferably the coating is a powder coating.Alternatively (or as well) a coating composition of the presentinvention may comprise a Second Polymer of the invention for example ifthe Third Process (polymerisation) is to occur in situ after the coatinghas been applied to an article.

[0195] Compositions of the invention may also comprise otheringredient(s) such as a carrier or diluent, conventionally used toformulate a composition and/or product effective (e.g. as a flameretardant) in the use for which it is designed. If the carrier ordiluent comprises a resin, the resin may be selected to optimise anysuitable property such as hardness or durability.

[0196] Compositions of the invention can be applied to any type ofsubstrate, such as, in particular, wood, textiles, paper and plastics,such as polyethylene and polypropylene. Such compositions can produce acoating which exhibits useful properties (such as flame retardancy) withgood resistance to external conditions. The compositions of theinvention can be used in applications such as, for example, plasticcoating, electric wire/cable, electronic sleeves, paper and board,automotive applications, textile, fabric coatings, carpets . . . .

[0197] Articles coated with a coating comprising a Third Polymer of thepresent invention also form part of the present invention.

[0198] A still yet further aspect of the present invention provides a) aproduct; b) a component for said product; and/or c) a consumable for usewith said product, which comprises at least one First Polymer, SecondPolymer and/or Third Polymer of the present invention and has utility inone or more applications and/or uses described herein; preferablyselected from at least one of flame retardancy, anti-corrosion,pigmentary dispersion and/or adhesion promotion; more preferably flameretardancy.

[0199] Another aspect of the present invention provides use of at leastone First Polymer, Second Polymer and/or Third Polymer of presentinvention in the manufacture of a) an effective product of theinvention, b) component for said product(s); and/or c) a consumable foruse with said product(s).

[0200] Another aspect of the present invention is a polymer and/orprocess for preparing a polymer as described in any of the Examples 1 to15 herein.

[0201] The terms ‘optional substituent’ and/or ‘optionally substituted’as used herein (unless followed by a list of other substituents)signifies the one or more of following groups (or substitution by thesegroups): carboxy, sulpho, formyl, hydroxy, amino, imino, nitrilo,mercapto, cyano, nitro, methyl, methoxy and/or combinations thereof.These optional groups include all chemically possible combinations inthe same moiety of a plurality (preferably two) of the aforementionedgroups (e.g. amino and sulphonyl if directly attached to each otherrepresent a sulphamoyl group). Preferred optional substituents comprise:carboxy, sulpho, hydroxy, amino, mercapto, cyano, methyl and/or methoxy.

[0202] The synonymous terms ‘organic substituent’ and “organic group” asused herein (also abbreviated herein to “organo”) denote any univalentor multivalent moiety (optionally attached to one or more othermoieties) which comprises one or more carbon atoms and optionally one ormore other heteroatoms. Organic groups may comprise organoheteryl groups(also known as organoelement groups) which comprise univalent groupscontaining carbon, which are thus organic, but which have their freevalence at an atom other than carbon (for example organothio groups).Organic groups may alternatively or additionally comprise organyl groupswhich comprise any organic substituent group, regardless of functionaltype, having one free valence at a carbon atom. Organic groups may alsocomprise heterocyclic groups which comprise univalent groups formed byremoving a hydrogen atom from any ring atom of a heterocyclic compound:(a cyclic compound having as ring members atoms of at least twodifferent elements, in this case one being carbon). Preferably the noncarbon atoms in an organic group may be selected from: hydrogen, halo,phosphorus, nitrogen, oxygen and/or sulphur, more preferably fromhydrogen, nitrogen, oxygen and/or sulphur.

[0203] Most preferred organic groups comprise one or more of thefollowing carbon containing moieties: alkyl, alkoxy, alkanoyl, carboxy,carbonyl, formyl and/or combinations thereof; optionally in combinationwith one or more of the following heteroatom containing moieties: oxy,thio, sulphinyl, sulphonyl, amino, imino, nitrilo and/or combinationsthereof. Organic groups include all chemically possible combinations inthe same moiety of a plurality (preferably two) of the aforementionedcarbon containing and/or heteroatom moieties (e.g. alkoxy and carbonylif directly attached to each other represent an alkoxycarbonyl group).

[0204] The term ‘hydrocarbo group’ as used herein is a sub-set of aorganic group and denotes any univalent or multivalent moiety(optionally attached to one or more other moieties) which consists ofone or more hydrogen atoms and one or more carbon atoms. Hydrocarbogroups may comprise one or more of the following groups. Hydrocarbylgroups comprise univalent groups formed by removing a hydrogen atom froma hydrocarbon. Hydrocarbylene groups comprise divalent groups formed byremoving two hydrogen atoms from a hydrocarbon the free valencies ofwhich are not engaged in a double bond. Hydrocarbylidene groups comprisedivalent groups (represented by “R₂C═”) formed by removing two hydrogenatoms from the same carbon atom of a hydrocarbon, the free valencies ofwhich are engaged in a double bond; Hydrocarbylidyne groups comprisetrivalent groups (represented by “RC═”), formed by removing threehydrogen atoms from the same carbon atom of a hydrocarbon the freevalencies of which are engaged in a triple bond. Hydrocarbo groups mayalso comprise saturated carbon to carbon single bonds; unsaturateddouble and/or triple carbon to carbon bonds (e.g. alkenyl, and/oralkynyl groups respectively) and/or aromatic groups (e.g. aryl) andwhere indicated may be substituted with other functional groups.

[0205] The term ‘alkyl’ or its equivalent (e.g. ‘alk’) as used hereinmay be readily replaced, where appropriate and unless the contextclearly indicates otherwise, by terms encompassing any other hydrocarbogroup such as those described herein.

[0206] Any substituent, group or moiety mentioned herein refers to amonovalent species unless otherwise stated or the context clearlyindicates otherwise (e.g. an alkylene moiety may comprise a bivalentgroup linked to two other moieties). A group which comprises a chain ofthree or more atoms signifies a group in which the chain wholly or inpart may be linear, branched and/or form a ring (including spiro and/orfused rings). The total number of certain atoms is specified for certainsubstituents for example C_(1-r)organo, signifies an organic grouphaving from 1 to ‘r’ carbon atoms. In any of the formulae herein if oneor more ring substituents are not indicated as attached to anyparticular atom on the ring, the substituent may replace any hydrogenatom attached to a ring atom and may be located at any availableposition on the ring which is chemically suitable.

[0207] Preferably any of organic groups listed above comprise from 1 to36 carbon atoms, more preferably from 1 to 18. It is particularlypreferred that the number of carbon atoms in an organic group is from 1to 10 inclusive.

[0208] The term “polyol” is understood to mean a compound or polymerwhich comprises at least two hydroxy groups not bound to the samecarbon.

[0209] The term oxirane is understood to mean a species comprising atleast one oxiranyl radical (also referred to herein as an oxiranylgroup). Oxiranyl radicals comprise a 3 to 6 membered saturatedheterocyclic ring which contains one oxy group with a free carbonvalence on the ring and/or a direct carbon bond from the ring to anotherorgano moiety (e.g. where the oxiranyl group comprises part of a largermolecule).

[0210] Preferred oxiranyl radicals comprise epoxide radicals and/oroxetanyl radicals. An epoxide radical may be denoted by the general

[0211] and an oxetanyl radical may be denoted by the general formula::

[0212] where independently in each case R″ denotes H and/or an organogroup, (preferably H and/or hydrocarbo) and at least one R″ denotes adirect carbon bond to another moiety or a free carbon valence. Compoundscomprising respectively epoxide and oxetanyl radicals may be referred torespectively as epoxide(s) and oxetane(s).

[0213] Oxiranes includes monooxiranes with one oxiranyl radical andpolyoxiranes which comprise at least two oxiranyl radicals for examplepolyepoxides such as diepoxides and/or polyoxetanes. Oxiranes comprisesspecies where the oxiranyl group is terminal or internal, preferablyterminal.

[0214] As used herein chemical terms (other than IUAPC names forspecifically identified compounds) which comprise features which aregiven in parentheses—such as (alkyl)acrylate, (meth)acrylate and/or(co)polymer—denote that that part in parentheses is optional as thecontext dictates, so for example the term (meth)acrylate denotes bothmethacrylate and acrylate.

[0215] Unless the context clearly indicates otherwise, as used hereinplural forms of the terms herein are to be construed as including thesingular form and vice versa.

[0216] The term “comprising” as used herein will be understood to meanthat the list following is non-exhaustive and may or may not include anyother additional suitable items, for example one or more furtherfeature(s), component(s), ingredient(s) and/or substituent(s) asappropriate.

[0217] The term ‘effective’ (for example with reference to the process,uses, products, materials, compounds, monomers, oligomers, polymerprecursors and/or polymers of the present invention) will be understoodto denote utility in any one or more of the following uses and/orapplications: anti-corrosion, pigmentary dispersion; adhesion promotionand/or flame retardancy, preferably flame retardancy. Such utility maybe direct where the material has the required properties for theaforementioned uses and/or indirect where the material is used as asynthetic intermediate and/or diagnostic tool in preparing materials ofdirect utility. Preferred uses are those which are necessary to provideimproved protection and/or resistance to flame and/or a source of heatand/or ignition. When referring to the effective materials of thepresent invention it is preferred that the term ‘optionally substituted’does not include halo containing species. As used herein the term“suitable” denotes that a functional group is compatible with producingan effective product.

[0218] The substituents on the repeating unit may be selected to improvethe compatibility of the materials with the polymers and/or resins inwhich they may be formulated and/or incorporated to form a flameretardant material. Thus, the size and length of the substituents may beselected to optimise the physical entanglement or interlocation with theresin or they may or may not comprise other reactive entities capable ofchemically reacting and/or cross-linking with such other resins.

[0219] Certain moieties, species, groups, repeat units, compounds,oligomers, polymers, materials, mixtures, compositions and/orformulations which comprise some or all of the invention as describedherein may exist as one or more stereoisomers (such as enantiomers,diastereoisomers and/or geometric isomers) tautomers, conformers, salts,zwitterions, complexes (such as chelates, clathrates, interstitialcompounds, ligand complexes, organometallic complexes,non-stoichiometric complexes, solvates and/or hydrates); isotopicallysubstituted forms, polymeric configurations [such as homo or copolymers,random, graft or block polymers, linear or branched polymers (e.g. starand/or side branched), cross-linked and/or networked polymers, polymersobtainable from di and/or tri-valent repeat units, dendrimers, polymersof different tacticity (e.g. isotactic, syndiotactic or atacticpolymers)]; polymorphs (such as interstitial forms, crystalline formsand/or amorphous forms), different phases, solid solutions; combinationsthereof and/or mixtures thereof. The present invention comprises allsuch forms which are effective.

[0220] The polymers of the present invention (First, Second and/or ThirdPolymers) may be prepared using one or more suitable polymerprecursor(s) (including where appropriate polymers of the presentinvention) which may be organic and/or inorganic and comprise anysuitable (co)monomer(s), (co)polymer(s) [including homopolymer(s)] andmixtures thereof which comprise suitable polymerisable functionality forexample moieties which are capable of forming a bond with the or eachpolymer precursor(s) to provide chain extension and/or cross-linkingwith another of the or each polymer precursor(s) via direct bond(s) asindicated in the Formulae herein. The polymer precursor(s) may besubstantially un-reactive at normal temperatures and pressures.

[0221] Preferably all the reagents, (and if required any optionalsolvents, catalysts and/or other materials) used in the processes of theinvention are substantially free of halo (per se and/or as impurities)so that the First, Second and/or Third Polymers of the invention soobtained are also substantially free of halo, without any furtherpurification steps being required.

EXAMPLES

[0222] The present invention will now be illustrated by the following,non-limiting Examples, in which the following conventional techniqueswere used: acid numbers were measured using American Standard method(ASTM) D 974-64; hydroxy (OH) numbers were measured using ASTM E 222-73;isocyanate (NCO) numbers were measured using ASTM D 2572-87; Hopplerviscosity (denoted herein by “H”) was measured at 25° C. using DIN53015; colour was measured using the Gardner method as described in ASTM1544-68;; and phosphorus content was calculated as the percentage massof phosphorus atoms compared to the total mass of the relevant productas the context dictates (denoted herein by P wt %).

Examples 1 to 5

[0223] The First Process and First Polymers of the present inventionwill now be illustrated. A generic First Process for preparing aphosphorus containing reactive (polyhydroxy terminated) polyesteroligomer (≡First Polymer) is now described

[0224] To a 4 litre reactor vessel having a heating jacket and equippedwith a stirrer, were added: ‘a’ g of the diol ‘b’; ‘c’ g of the diacid‘d’; ‘e’ g of 2-methenyl-1,4-butandioic acid (itaconic acid); ‘f’ g of9,10-dihydro-9-oxa-10-phosphaphenantrene-10-oxide (also referred toherein as DOPO and available commercially from Schill & Seilacher underthe trade name Struktol Polydis 3710); 2.0 g of 1,4 dihydroxybenzene(hydroquinone, an anti-oxidant); and 1.2 g of the tin catalyst availablecommercially from Goldschmidt under the trade name Fascat 4102. Thereaction mixture was stirred and heated to 110° C. under a stream ofnitrogen at a flow rate of 5 litres per hour. The mixture was held atthis temperature for 4 hours and then heated to 180° C. until no morewater distilled (‘g’ g of water produced from the esterificationreaction was collected). When the acid value reduced to less than 10 mgKOH/g, the reaction mixture was heated at 180° C. under reduced pressurevacuum for 8 hours to remove residual water. The mixture was cooled atroom temperature until ³¹P-NMR analysis confirmed that the addition ofDOPO onto the unsaturated bonds of itaconic acid was complete (i.e. nofree DOPO was detected) to give as product a phosphorous-containingpolyester acrylate polymer with the following properties: Phosphoruscontent of ‘h’% w/w; acid value (I_(AC)) of ‘i’ mg KOH/g; and hydroxyvalue (I_(OH)) of ‘j’ mg KOH/g.

[0225] In the generic First Process of the invention described above,the diol ‘b’ corresponds to component (iii); the diacid ‘d’ correspondsto optional component (ii); the itaconic acid corresponds to component(i); and the DOPO corresponds to component (iv). The specific Examples 1to 5 (examples of First Polymers of the invention) were prepared by theabove described generic First Process with reference to Table 1 below.TABLE 1 I_(AC) Diacid ITA DOPO H₂O P wt % ‘i’ mg I_(OH) Diol wt Diol wtDiacid wt wt wt ‘h’ / KOH/ ‘j’ mg Ex ‘a’ / g ‘b’ ‘c’ /g ‘d’ ‘e’ / g ‘f’/ g ‘g’ / g % g KOH /g 1 1,323.7 DHE 267.8 ADP 905.3 1503.2 240 5.57 8.2108.2 2 1612.3 TPG 267.8 ADP 905.3 1503.2 240 5.39 11.25 25.75 3 1408.2HD 290.5 IPH 865.0 1436.3 235 5.53 5.09 70.16 4 896.6 HD 0 None 790.31313.1 235 6.78 6.2 53.6 5 1067.0 HD 193.4 ADP 653.9 1085.7 180 5.39 9.271.4

[0226] In Table 1: DHE denotes 1,2-dihydroxy ethane (ethylene glycol);TPG denotes tripropylene glycol; HD denotes 1,6-hexane diol; ADP denotes1,6-hexanedioic acid (adipic acid); IPH denotes 1,3-benzene dicarboxylicacid (isophthalic acid); and ITA denotes 2-methenyl-1,4-butanedioic acid(itaconic acid.

Example 6 Phosphorus Containing Polycarboxylic Acid Terminated Polyester(≡First Polymer)

[0227] A process for preparing a phosphorus containing reactive(polycarboxy terminated) polyester oligomer (≡First Polymer) is nowdescribed. To a suitable reaction vessel 1,256 g of 1,3 benzenedicarboxylic acid (isophthalic acid); 471.8 g of2-methenyl-1,4-butanedioic acid (itaconic acid); and 1,061 g of2,2-dimethyl-1,3-propanediol (neopentyl glycol) were admixed togetherwith 0.25% of the tin polycondensation catalyst available fromGoldschimdt under the trade name Fascat 4102. The reaction mixture washeated to a temperature of 235° C. When the reaction mixture becamelimpid a reduced pressure was gradually applied to the vessel andmaintained until following characteristics were met: acid number: 42.5±2mg KOH/g; and hydroxyl number: <4 mg KOH/g to form a polycondensationproduct which was then reacted directly with 784.1 g of DOPO which wasadded at a temperature of 200° C. The reaction mixture is then stirredfor minimum of four hours at 200° C. to complete the addition reactionuntil the following characteristics were met: acid number: 35±3 mg KOH/gto give as product a phosphorus containing polycarboxylic acidterminated polyester. The reactive polymer precursor of Example 6 hereincan be used directly in Example 14 to make a UV curable polyester usefulin powder coating applications.

[0228] The Second Process and Second Polymers of the present inventionwill now be illustrated.

Examples 7 to 11

[0229] A generic Second Process for preparing a phosphorus containingpolyester acrylate polymer precursor (≡Second Polymer) is now described

[0230] To a 1.5 litre double jacketed reactor vessel connected to an oilbath and equipped with a stirrer, was added ‘a’ g of the phosphoruscontaining reactive polyester oligomer (made as described in Example‘b’); ‘c’ g toluene; ‘d’ g propenoic acid (acrylic acid); ‘e’ g of4-methylphenyl sulphonic acid monohydrate (p-toluenesulphonic acidmonohydrate or PTSA.H₂O) and ‘f’ g of 4-methoxyphenol (mono methyletherhydroquinone or MEHQ—an antioxidant). The reaction mixture was stirredand heated under reflux until no more water is distilled.

[0231] The reaction mixture was cooled down to 50° C. and diluted with‘g’ g of toluene. The reaction mixture was washed 3 times with 15%aqueous solution of sodium sulphate (10% by volume related to theorganic phase) and the organic phase was recovered and heated to 85° C.in the presence of ‘h’ g of 4-methoxyphenol. Water was then removed byazeotropic distillation under reduced pressure. Once no more waterseparated, the organic mixture was filtered at 50° C. under pressure (6bar). The same amount of additional 4-methoxyphenol (‘h’ g) and ‘i’ g oftris(para-nonylphenyl)phosphite (TNPP, CAS no. 26523-78-4, anantioxidant stabiliser) was added to the filtrate and the mixture washeated to 85° C. and toluene was removed by distillation under reducedpressure. When all the toluene had been removed ‘j’ g of1,4-dihydroxybenzene (hydroquinone or HQ—an anti-oxidant) was added tostabilise the resulting product.

[0232] Optionally the p-toluenesulphonic acid (PTSA) catalyst may beremoved by precipitating it from the product using suitable base “k”(which may be a weak or a strong base) in which case an aqueous washingstep is avoided which increases the yield of the highly hydrophillicproduct. However if a base is not used the product was simply washedwith a 20% aqueous solution of Na₂SO₄.

[0233] In either case a phosphorus containing polyester acrylate polymerprecursor was obtained which determined to have the followingproperties: the phosphorus content of ‘l’% w/w; Hoppler viscosity (H,60° C.) of ‘m’ mPa.s; colour measured following the Gardner method of‘n’ G; acid value (I_(AC)) of ‘o’ mg KOH/g: and a hydroxy value (I_(OH))of ‘p’ mg KOH/g.

[0234] Examples 7 to 11 (examples of Second Polymers of the Invention)were prepared by the above described generic Second Process withreference to Tables 2 and 3 below. TABLE 2 Wt 1^(st) 1^(st) PTSA.H₂OMEHQ MeHQ TNPP Polymer Polymer Tol wt AA wt wt wt Tol wt wt wt Ex ‘a’ /g ‘b’ / Ex ‘c’ /g ‘d’ / g ‘e’ / g ‘f’ / g ‘g’ / g ‘h’ / g ‘i’ / g 7 5001 245 72.1 8.58 1.22 191.0 0.48 0 8 750 3 346 74.6 17.3 1.73 478.6 0.582.3 9 750 4 529 56.9 19.8 1.98 277.9 0.66 2.65 10 750 5 538 75.7 20.22.02 287.7 0.67 2.69 11 750 5 538 75.7 20.2 2.02 None 0.67 2.69

[0235] TABLE 3 Ex HQ wt Base P wt % H (60° C.) Colour I_(AC) - ‘o’ mgI_(OH) - ‘p’ mg (cont.) ‘j’ / g ‘k’ ‘l’ / % ‘m’ / mPas ‘n’ / G KOH / gKOH / g 7 0.12 None 5.1 17,250 1.5 10 20 8 0.23 HMDA 5.1 NM NM 15 27 90.26 HMDA 6.4 NM NM <15 <15 10 0.27 HMDA 5.0 NM NM <15 <15 11 0.27 NaOH5.0 NM NM 8.7 15.7 50% aq

[0236] In Tables 2 and 3: Tol denotes toluene; AA denotes acrylic acid;PISA.H₂O denotes p-toluenesulphonic acid monohydrate; MEHQ denotes4-methoxyphenol (mono methylether hydroquinone); TNPP denotestrisnonylphenylphosphite; HQ denotes 1,4-dihydroxybenzene(hydroquinone); HMDA denotes 1,6-hexamethylenediamine; and NM indicatesthe property was not measured.

[0237] Flame Retardancy Tests

[0238] The flame retardant properties of various coatings and/or filmsmade from a phosphorus containing polyester acrylate polymer precursorof the invention (Example 7) were assessed by several conventionalmethods as follows.

[0239] A coating composition was prepared by diluting 70 parts ofExample 7 with. 30 parts of tripropylene glycol diacrylate (alsoreferred to herein as TPGDA); 4 parts of a photoinitiator (thatavailable commercially from Ciba under the trade name Irgacure 500); and5 parts of an amine co-activator (that available commercially from UCBChemicals under the trade name Ebecryl 7100). The composition wasapplied to a 230 mm×1050 mm substrate of MDF (8 mm thick) with a beechveneer (1 mm thick) with a roller coater and cured with UV radiation (80W, Hg lamp) to form a film of 2×50 micron thickness which was tested asfollows.

[0240] Radiant Flooring Panel Test

[0241] The coated substrate was tested in a standard radiant flooringpanel test (as described in standard prEN 9239-1). The distance of flamespread was 30 cm with a critical radiant flux of 0.75 Wcm⁻². As acomparison a prior art aliphatic urethane acrylate coating (thatavailable from UCB Chemicals under the trade designation EB 284) wasapplied to the same substrate with the same thickness and gave in thesame test a flame spread of 42 cm with a critical radiant flux of 0.50Wcm⁻².

[0242] Vertical Radiant Panel Test

[0243] The coated substrate was tested in a flame extinguish test (asdescribed in standard CSE RF 3/77) and the results are given below,where for comparison the results for the same substrate uncoated arealso given in parentheses. The time for the flame to extinguish was1,053 seconds (>1,100 s); rate of flame spread (mm/min) was 29.63seconds (30.3 s); and extent (maximum length) of damage was 520 mm(higher than 600 mm).

[0244] Limiting Oxygen Index (LOI) and Thermogravimetric Analysis (TGA)

[0245] A further coating composition was prepared by diluting 70 partsof Example 7 with 30 parts of TPGDA. The composition was applied to asubstrate with a bar coater and cured with electron beam radiation (5Mrad, 250 keV, 20 m/min) to form a film of 100 micron thickness whichwas denoted as F7.

[0246] F7 was submitted to a thermogravimetric analysis (TGA) in whichthe sample was heated at a rate of 10° C./min under air atmosphere fromroom temperature up to 700° C. The weight % residues at 500° C. and at600° C. in the TGA test described herein for the polyester acrylate ofthe invention herein (Example 7) was compared with a non phosphorouscontaining film made from a prior art urethane acrylate (EB 284) alone.At a given temperature, a higher char yield indicated that the materialis a better flame retardant. The oxygen index (OI) was determined byusing ASTM D 2863 for measuring the minimum oxygen concentration tosupport candle-like combustion of plastics. The test was applied tomaterial of thickness 150 μm, using a test specimen of dimensions of 52mm×140 mm.

[0247] Following the publication of M. Levin, S. M. Atlas, Eli M.Pearce, “Flame-Retardant Polymeric Materials”, Eds., Plenum Press,New-York (1975), p.376; a sample that has a Limit Oxygen Index (referredto herein as LOI) measured as described herein which is higher than 20%is considered to be a flame retardant, either a slow burning composition(20%<LOI<27%) or a self extinguishing composition (LOI>27%). It can beseen from the data in Table 4 that the Example of the present inventiontested can thus considered to be flame retardants by this definition.

[0248] The char yields and LOI of a phosphorus containing polyesteracrylate of the present invention can be compared with the char yieldsand LOI of a prior art urethane acrylate. The data in Table 4 show thatcompared to prior art material, char yields and/or LOI are much higherfor films of the present invention than the comparative example,illustrating the improved flame retardant properties of the phosphorouscontaining polyester acrylates of the invention. TABLE 4 Char Yield (%)Char Yield (%) Example @ 500° C. @ 600° C. P % (w/w) LOI % EB 284 11  10 18.0 F7 30 21 3.3 22.6

Example 12 Alternative Preparation of Polymer with Structure of Example8 (≡Second Polymer)

[0249] A Second Polymer of the invention having the same structure asExample 8 herein, may solubilised as follows. To a double jacketedreactor of 0.5 litre connected to an oil bath and equipped with astirrer were added 100 g of toluene and 200 g of the phosphoruscontaining reactive polyester oligomer of Example 8 (made analogously tothe generic method described above and in Tables 2 & 3, the polymerhaving 1.63 meq DOPO/g). The reaction mixture was stirred and heated to30° C. Then 7.6 g of sodium hydroxide in solution in 7.6 g water wasslowly added to the reaction mixture. When the pH became neutral, 100 gof water was added and the reaction mixture was stirred for 10 minutes.The water phase, containing the water-soluble polyester acrylate, wasdecanted. ³¹P-NMR analysis of the water phase showed appearance of a newmajor peak (24.5-23.2 ppm) corresponding to the phosphinic sodium saltformed from hydrolysed DOPO).

Example 13 Phosphorus Containing Polyester Urethane Acrylate (≡SecondPolymer)

[0250] A phosphorus containing polyester urethane acrylate polymerprecursor of the present invention was prepared as follows. To a onelitre double jacketed reactor vessel connected to an oil bath andequipped with a stirrer, was added 404 g of the phosphorus containingdiol (prepared analogously as described in Example 1, with an acid valueof 108.2 mg KOH/g), 173.2 g of isophoronediisocyanate (IPDI) and 0.76 gof 1,4-dihydroxybenzene (hydroquinone—an anti-oxidant). The reactionmixture was stirred and heated to 70° C. Then 0.1 g ofdibutyltindilaurate (DBTL, (C₄H₉)₂Sn(OOC₁₁H₂₃)₂) was added and thereaction mixture was stirred until the isocyanate value was lower than1.35 meq/g. 1,6-hexanedioldiacrylate (HDDA) (254 g) was then added tolower the viscosity. The reaction mixture was cooled down to 60° C. anda mixture of 2-hydroxyethylacrylate (90.5 g) and dibutyltindilaurate(0.1 g) were added dropwise through a dropping funnel over a period of30 minutes. After the exothermic reaction was completed, the reactionmixture was heated to 90° C. and stirred until the isocyanate value waslower than 0.15%. The mixture was then cooled down, and hydroquinone(0.76 g) and TNPP (0.76 g) were added to stabilise the resultant productwhich was a phosphorus containing urethane acrylate with the followingproperties: Hoppler viscosity (H, 60° C.)=9200 mPa.s and colour measuredfollowing the Gardner method <1 G and residual NCO <0.15%.

Example 14 Preparation of a Phosphorus Containing UV CurableGlycidylated Polyester Useful in Powder Coating Applications (≡SecondPolymer)

[0251] The product of Example 6 (a phosphorus containing polycarboxylicacid terminated polyester) was used directly in the following process toprepare a UV curable glycidylated polyester useful in powder coatingapplications. Air was added to the direct product of Example 6 at atemperature between 160° C. and 170° C. and 0.5% ethyl triphenylphosphonium bromide (calculated on total amount of resin) and 1.2%di-tert-butyl-hydroquinone (calculated on the amount of glycidylmethacrylate) were added in the reaction mixture. After that, 95% of thetheoretical amount of glycidylmethacrylate, (GMA)

[0252] recalculated on the practical acid number of Example 6, wasgradually added In a time of a half-hour. The reaction mixture was thenstirred for another two hours at 170° C. until following characteristicswere met: acid number ≦2 mg KOH/g to form a phosphorous containingpolyester which can be used in UV curable powder coating formulations.

[0253] Flame Retardancy Test

[0254] The flame retardant properties of a powder coating made from thepreceding phosphorus containing glycidylated polyester of Example 14were assessed as follows.

[0255] A powder coating composition was prepared by adding to 71.5 parts(by weight) of the polyester of Example 14; 25 parts Kronos 2160, 2.5parts of photoinitiator (1 to 1 mixture of those available commerciallyfrom Ciba under the trade names Irgacure 2959 & Irgacure 819); and 1.0parts of a flow additive (that available commercially from Worlée underthe trade name Resiflow RV5). The composition was extruded through adouble screw extruder (24 to 1 ratio of length to diameter) at atemperature of 80° C. and torque of 80% and the extrudate was pre-groundand fine milled to a suitable particle size.

[0256] The powder composition was applied to a substrate of MDF (8 mmthick) with a beech veneer (0.5 mm thick) with a corona gun (GEMA) toform a coating 70 microns thick. The coating was melted by a combinationof IRM and convention at 110° C. and then cured with UV radiation (agallium doped Hg lamp and a Hg lamp 160 Wcm⁻¹) at a speed of 3 m(min)⁻¹.

[0257] A 10 cm×10 cm sample of the coated substrate was tested in a conecalorimeter test (as described in standard ISO 5660 at a flux level of19 kWm⁻²) where the rate of heat release (in kWm⁻²) was recorded as afunction of time. The results are given below, where for comparison theresults for the same substrate coated with the same thickness of a knownwhite, textured, powder coating (that available commercially from UCBChemicals under the trade name Uvecoat 2100) are also given inparentheses. The ignition time was 340 seconds (293 s) and the peak ofheat release was 175 kWm⁻² at 384 seconds (224 kWm⁻² at 326 seconds).

Example 15 Incorporation of a Phosphorous Containing Polyester into anUV-Crosslinkable Polyurethane Dispersion

[0258] To a double jacketed reaction vessel, connected to an oil bathand equipped with a stirrer, were added 277.0 g of thephosphorous-containing reactive polyester oligomer (prepared analogouslyto that described in Example 1), 52.6 g of dimethylolpropionic acid(DMPA), 264.0 g of acetone, 286.9 g of dicyclohexylmethylenediisocyanate(H₁₂MDI available from Bayer under the trade name Desmodur W) and 88 mgof dibutyltindilaurate (DBTL). The reaction mixture was stirred andheated at 60° C. until an isocyanate value of 0.98 meq/g was obtainedThen 60.1 g of 2-hydroxyethylacrylate (HEA) and 188 mg ofmethyletherhydroquinone (MEHQ) were added and the reaction was stirredat 60° C. until an isocyanate value of 0.37 meq/g was obtained at whichpoint the reaction mixture was cooled down to 45° C. Then 40.0 g oftriethylamine (TEA) were slowly added to the reaction mixture. The TEAwas allowed to react for 15 minutes with the free carboxylic acid groupscoming from the DMPA, thus providing the polyurethane-acrylate withionic character.

[0259] Meanwhile a double-jacketed dispersion vessel, connected also toan oil bath and provided with a stirrer, was charged with 1273 g ofdistilled water. Then the content of the reaction vessel was slowlydischarged into the dispersion vessel under a high stirring rate to forma dispersion. After the discharge was complete, stirring was continuedfor half an hour. Then the dispersion vessel was heated and the acetoneremoved by vacuum assisted distillation at a mass temperature of 50° C.to 60° C. until the acetone content was lower than 0.15%. Then thedispersion vessel was cooled down to room temperature and the dry mattercontent of the dispersion adjusted to 35% by adding a calculated amountof distilled water. Finally 1.96 g of Acticide AS fungicide was added toobtain as product a dispersion with the following properties: viscosityof 29 mPa.s (measured on Brookfield viscometer at 25° C. with spindle 2at 50 RPM); dry matter content of 35.1%. The product was tack free afterthe water had evaporated from the dispersion.

1. A process for preparing a phosphorus-containing polymer precursorwhich polymer precursor is a radiation-curable polyester, the processcomprising the steps of (a) mixing together: (i) a compound containingat least one hydrocarbylidenically unsaturated group and a plurality ofcarbonyloxy groups; (v) optionally a compound having a plurality ofcarbonyloxy groups and optionally free of hydrocarbylidenicallyunsaturated groups, (vi) a polyol, and (vii) anoxyphosphorous-containing compound (component (iv)) in which thephosphorous atom has at least one P—C bond which is resistant tohydrolysis or transesterification under the reaction conditions herein;such component (iv) comprising compounds of formula (I) and/or (II)and/or effective isomers, salts and mixtures thereof: R¹ R² R³P═O   (I)

 where, in formula (I): at least R¹ and R² independently representsC₁₋₂₀organo group substituted by one or more hydroxy and/or carboxygroup; R³ represents H or optionally substituted C₁₋₂₀organo group; informula (II): the phosphorous atom is substituted with at least onecarbon atom to form at least one P—C bond; the P—O bond forms part of anorgano ring, the ring being optionally substituted with one or moreorgano groups and/or optionally fused to one or more other organo rings;(b) initiating polymerisation of the mixture to form a hydroxy and/orcarboxy terminated phosphorous containing polyester oligomer (“FirstPolymer”), (c) reacting the First Polymer with at least one acrylatingagent to form a radiation-curable polymer precursor (“Second Polymer”).2. A process as claimed in claim 1, in which a catalyst is presentduring step (a) which catalyst (component (v)) comprises a tin complexcatalyst.
 3. A process as claimed in claim 1 or 2, wherein theoxyphosphorous-containing compound of formula (I) comprises at least oneof: bis(hydroxymethyl)isobutylphosphineoxide,bis(hydroxypropyl)isobutylphosphine oxide and trishydroxymethylphosphineoxide.
 4. A process as claimed any preceding claim, wherein theoxyphosphorous-containing compound of formula (II) comprises:

in which R² to R⁵ independently represent H or optionally substitutedC₁₋₁₈organo group(s), a plurality of which may together represent one ormore rings optionally fused to the oxyphosphorous ring to which they areattached.
 5. A process as claimed in any preceding claim, wherein theoxyphosphorous-containing compound of formula (II) comprises:

9,10-dihydro-9-oxa-10-phosphaphenantrene-10-oxide.
 6. A process asclaimed in any preceding claim, which comprises a further step (step(d)) where the reaction product is neutralised with a base and water isremoved from the reaction mixture before the resultant product isisolated.
 7. A process as claimed in any preceding claim, wherein the“First Polymer” is reacted with an oxiranating and/or isocyanatingagent.
 8. A polymer obtained or obtainable from the process as claimedin any preceding claim.
 9. A polymer as claimed in claim 8 comprisingoptionally substituted phosphorous containing polyester urethane(meth)acrylates.
 10. A process comprising a polymerisation method forpreparing a phosphorus-containing polyester derived polymer byinitiating polymerisation in the presence of the polymer as claimed inclaim 8 or 9, and which optionally may be used as a reagent, and/orco-monomer in combination with other ingredients selected from(co)monomers, polymer precursors, catalysts, initiators, cross-linkers,flame retardant additives and/or other additives.
 11. A polymer (“ThirdPolymer”) obtained or obtainable from the process as claimed in claim10.